replacement parts

deernrams

Cadet
Joined
Mar 9, 2007
Messages
19
Hi all. I have a 1970 115hp in line 6 outboard. Serial number is 2933436. I believe it is one of the last attributed to 1970. I am looking for the distributor shaft, part number 4312. It's the little bug on the end of the shaft. Sorry, bug is not a technical term. Every so often I see some of these older mercs on craigslist. Where can I find out how many years this shaft is interchangeable with mine? Did they use the same dissy assembly from 1970 - 1973,75,79. Where can I find out how many other parts can be used from different years. Thx in advance.
 

Droll

Chief Petty Officer
Joined
Jul 30, 2003
Messages
514
Re: replacement parts

They used the same shaft/rotor from 1970 up to the end in mid 1979.

This shaft are NLA from Mercury ( last know prize was $462.46 ), but you can get an after marked part here .


Arne Kjetil
 

deernrams

Cadet
Joined
Mar 9, 2007
Messages
19
Re: replacement parts

I have the new housing with new wires going into that hard plastic. We broke the bug on the old shaft putting it together. I did come across Mage Marine web site. They say 393-4371 and 393-4312 are the same and will fit most 4 and 6 cylinders from 1970-79. Has any1 had any dealings with this company? The distributor rotor and shaft is 167.00 plus shipping. I guess this is the one I need, my old bug/rotor had 4312 on it. I gotta ask does anybody have a blown motor that I could buy shaft and rotor off of? I will keep searching craigs and ebay, but I think it is a long shot. Thx in advance.
 

Moody Blue

Captain
Joined
May 24, 2004
Messages
3,136
Re: replacement parts

I've read your post several times and still not really sure what it is that you are looking for. Can you elaborate a little more on what you are calling a bug.
 

sschefer

Rear Admiral
Joined
Nov 13, 2008
Messages
4,530
Re: replacement parts

I've read your post several times and still not really sure what it is that you are looking for. Can you elaborate a little more on what you are calling a bug.

Pretty sure he's talking about the rotor.
 

deernrams

Cadet
Joined
Mar 9, 2007
Messages
19
Re: replacement parts

Yes, the rotor. One of my posts I said bug/rotor. Speaking of calling it the right thing, the place where the 3 wires go into the housing assembly into that hard plastic and go half way around. Is that considered the trigger? ( ya I know I'm learning) I cannot find where it specifically says that in my Mercury manual 1966 thru 1974. It's too bad that plastic and wires don't come out like some do. So in conclusion, I do have the new housing assembly with the trigger built in. I have the shaft, just don't have a rotor on it. I guess the shaft and rotor is one piece. Anyway i need one. Can the general public buy from Mage Marine. They are the cheapest so far. Thx for your patience. Thx in advance.
 

Moody Blue

Captain
Joined
May 24, 2004
Messages
3,136
Re: replacement parts

Unfortunately the rotor is an integral part of the shaft and is not replaceable. As you've discovered, the replacment rotor/shaft is expensive.

This site has a good p/n cross reference feature. Type in the p/n and it shows all the models and years the part was/is used on.

http://www.boats.net/parts/detail/merc/M-4312.html

Looks like the 4312 was used on the in-line 6 motors between 1970 and 1979 and the 4371 used on the 800 and 850 motors between 1970 and 1975. Don't know what or if there is a difference.

CDI is a well known MFR of aftermarket ignition components and from their website they show that the 4371 is a replacement for the 4312. scroll down near the bottom of the page.

http://www.cdielectronics.com/Products.aspx?Criteria=9

This place has it a little cheaper

http://www.boatfix.com/bypartnokey.ASP?whichpage=55&pagesize=40&mfgitem=&make=Rapair+CDI
 

deernrams

Cadet
Joined
Mar 9, 2007
Messages
19
Re: replacement parts

Wow. Thx moody, that was some (fantastic) info. Can you tell me why this trigger was built into the housing assembly. I see some where the trigger can just be pulled out from housing. This one looks like some hard plastic was poured in the housing. Was this done to keep water out??? Thx again.
 
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